In the book of Matt 4, Christ Jesus told Peter, "follow me, and I will make you". The point is, following Christ Jesus is indispensable to being made by Him. And the problem is, a lot of men and woman desire to be made by Him, yet, detest to follow him.
Ministry is running a divine errand – being sent on a mission with a message to a specific people. Also, ministry is the pursuit of God-given vision. The point is, it is one thing to be in the ministry, and it's another (big) thing to be effective in it. And effectiveness in ministry requires that one has followed Christ Jesus passionately and faithfully.
Salvation (Being Born Again) is the B.A for ministry, while discipleship is the D.Min (Doctor of ministry). Discipleship prepares anyone for the work of ministry. For its in discipleship that people die to self and its lusts, while they grow unto maturity in the spirit (Christ likeness). And really, it takes the likes of Christ to do the works of Christ effectively.